BSA Scorpion,Ultra,R10 .25 single shot tray

Does anyone know if BSA makes a single shot tray for their .25 caliber guns? All I can see are the .177 , and .22 versions. I am wanting to try some Predator Polymags in .25, and they do not fit well and jam in the standard multishot magazine. Seems like I need the single load option, or for a .25 caliber Polymag "short" like they did for the .22 pellets that were having trouble cycling in magazines.